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"DoN. Nichols" wrote in message
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In article ,
Harold and Susan Vordos wrote:

"OldNick" wrote in message
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We had to pay to have 3 phase power run to our location. Just over 2
iles.
Got a damned good break because the single line serving our area was in
need
of upgrading anyway. We had to pay only for the third conductor, plus
the
distance from the main line to our property. Worth every penny when you
consider my need, owning a 50 KW induction furnace.

Beware of one problem -- assuming that you have a commercial
"demand" priced power, instead of domestic. (It is often the case that
the power company will not provide three-phase except under commercial
pricing.) That problem is that the pricing (usually for several months)
is based on the maximum load drawn within a fairly short period. So
fire up that 50 KW induction furnace, and you may find yourself paying
for power as though you were running that induction furnace full time.

Yep! They (PUD, Public Utility District) installed a demand meter. I'm
so far from being able to run the induction furnace at this point I'm not
too concerned, but it's a reality for the future. One of the good things
is that I have installed twin services, with everything running through the
single phase service that can be. Shop lights, all receptacles. There are
no single phase devices of any kind that get metered through the demand
meter. I was told that the cost increase would come at 50 KW, so unless I
draw a full load, I could avoid any overcharge. I'll be careful to keep
the compressor from running when I fire up the induction furnace, and
there's nothing else I'd possibly be doing aside from running it when it's
in operation. They require almost constant attention (old technology, not
solid state) to monitor power factor, which is constantly changing as the
metal melts.

Harold. Regarding the amps vs speaker wire thing. I would seriously
look at using signal lead, well-shielded and earthed and driving a new
amp, over running the power to speakers. If you have a listening room,
that's where you listen. The shed will prob. have **** acoustics, and
you are already distorting the sound if you introduce other sounds,
even if you raise the whole thing to tinnitus levels G

Yeah, I've already considered all that, but it's no different from what
I'm
used to in the shop environment. My plan is just a slight modification
of
something I have already done before, and I was pleased with how that one
turned out.

Is there a difference in the distance from the listening room to
the shop? (You may have spelled this out earlier in the thread, but I
came back from a couple of days away, and had so much to read that I
killed off several long threads, opting to read only what came in after
that point.)

Yes, a great distance. The listening room is just over 30' deep, with the
speakers on the opposite end of the room from the electronics. I have
installed EMT conduit in which I'll run some #10 appliance cord to each of 4
speakers positions. The runs are very nearly the same length, a few feet
different from one another, necessitated by the relative location, one from
another. The shop is a different critter. From the electronics to the
shop will be in the neighborhood of 120'. Not measured, but I have a fair
idea I'm very close. Long distance is the point, not just the next room.

I agree that you will get better sound from a less expensive
amplifier driving those speakers locally than from a long run with heavy
gauge wire. But -- what I would suggest that you use for the feed is
not plain shielded wire (which tends to pick up some hum over long
runs), but instead a 600 ohm balanced line driving one twisted pair
shielded per channel. The twisted pair tends to cancel out capacitive
and inductive coupling between the wires, and the balanced tends to
isolate from common mode voltage differences. Ideally, you would have
an excellent audio transformer at the input to the shop amp -- or an
input circuit which emulates that. This is the way that broadcast
audio, and recording studios route sound around without worrying about
the kind of noise pickup which normal shielded wire is vulnerable to.

Note that your Macintosh amplifier has provisions for accepting
600 ohm inputs (the three-pin connectors on the back panel, according
to the web site).

Unfortunately, my amp is not the one you're discussing. I run an old
Mc2300, built in the mid 70's. All connections from the preamp, in and out,
and the in connections on the amp are limited to RCA jacks. Mc used them
for years with no changes. The modern gear is a product of new ownership as
far as I know.

Ted's circuit may well do all that you need in the shop, and
there should be better control of the speakers with a local amp than
with one running through those long low-impedance cables which add
capacitive coupling between the conductors for one channel (which will
reduce high frequencies), and between the channels (which will cause
high frequencies intended for one channel to appear (somewhat weaker) in
the other. If your high current lines are all parallel as well, there
may also be inductive coupling.

Chuckle! Ted's a great guy, but he didn't offer me one of his amps, which
comes as no surprise.

Go ahead and run the high current wires -- but also run the
shielded twisted pair to allow a comparison test when you get a good
amplifier for the shop. They won't take up much space in the conduit.

I have 1½" conduit in place for the run, so it shouldn't be too crowded,
regardless. I'm thinking of installing a pull piece just in case I decide
to add something in the future, at which time I could pull a second pull
piece. I realize how difficult it can be to pull wire once some occupies
the space. Possible, but often very difficult, especially on turns.

And -- if possible, make your high current pairs twisted as well
(that is, both wires for a given channel are twisted together), which
will reduce some of the problems which they may introduce.

I like that idea and will do just that. Considering I'll be running two
pairs, would you recommend I twist each pair, then twist the two pairs of
pairs? Any benefit in doing so? In either case they'll be in the same
conduit, but with the twist, perhaps there's something to gain. From all
indications, I'll have to pull through only two 90's, so the overall large
bundle should pull fairly easily---especially considering I'll be using THHN
stranded wire.

I'm going to go with my original idea, if for no other reason, it served me
well in the past, although the run was considerably shorter. Power isn't
an issue, I have more than plenty, and loss at the high end isn't a concern,
not when listening in the shop, anyway. Like most of us, my high end
isn't what it used to be. I haven't heard the sound of a flyback
transformer in a TV for a long time.


A halfway decent amp will be better than all the crap you are going to
do to achieve controllable music in the shop. Crickey! Use an FM
transmitter! G

You have full control over volume. You can, if you wish, enter into a
full-fledged equaliser to compensate for room acoustics, volume, etc
etc. All onsite.

I had that, minus the equalizer (had it, but not on site) with my old
setup,
which I will emulate here. In fact, I have three sets of controls, the
autoformers I spoke of. They were purchased long ago, from a company in
Utah, where I used to reside, that specializes in sound distribution. I
was totally pleased with the performance they provided, and should be
again.

Do they change volume in steps (that is a tapped
autotransformer), or continuously variable (like a Variac designed for
audio power levels)?

Steps. The stainless steel face plate is calibrated 0 through 10 over about
320°.


In any case, they result in variable loads applied to the
amplifier in the listening room -- with might induce some distortion
there as well.

Again, I'm not nearly as concerned with that as I would be having to listen
to a radio, where I'm subjected to music I despise. Even the jazz station
we frequent, KPLU, which is found online, plays a fair amount of music I
don't prefer. They're big on vocalists, which, for the most part, I don't
like. Of late they're playing way too much Norah Jones. She's likely a
lovely lady, but I can't stand her voice, nor her choice of songs. Mostly
related to country music. I'd rather kiss a pig on the mouth than listen to
that stuff. Ella Fitzgerald, Sarah Vaughn, Joe Williams, Mel Tormè, Nat
King Cole, Sinatra--------No problem.

Perhaps the ability to listen in the shop without inflicting
your choices on your wife back in the main house? (I don't know how
good the acoustic isolation in your listening rom may be.)


I'm a lucky guy, DoN. My wife listens to and enjoys the same music, and we
agree almost perfectly on our likes and dislikes. Neither of us like
country western, and both of us prefer the baroque when listening to
classical. She almost always is listening when I am. Both of us are real
MJQ fans, along with many others. Brubeck happens to be a favorite for both
of us. Life is good!! When I'd be in the shop, she'd likely be listening
to the other speakers in the house, as has been our habit as long as we've
been married.

Is your amp going to be fed from recordings, or from a tuner?
The latter would be likely to require

You seem to have dropped the ball here, but to answer, I'd use the system in
all ways. Tuner (we have a McIntosh MR-78 FM tuner, and don't listen to AM)
plus various playback systems, including reel to reel (Crown CX 824),
cassettes (Nakamichi 1000 II) and an inexpensive Nakamichi CD player. We
still have the turntable and our large collection of vinyl recordings, but
they don't lend themselves to shop listening because of the distance to the
listening room from the shop. Too inconvenient. We plan to add a good
quality CD player, most likely a McIntosh, when we inhabit the house. Not a
worry meantime.

I'm quite happy with may Hafler amp (which was a kit), and you
might be as well. I presume that they are still made.

Could be I would be happy with it, but I'm not sure I'd be up to the task of
assembling one. The only amplifier I ever built was when I was just a
kid, hanging out at the local radio repair store. Built it from scratch
with the help of a guy that worked there, but it would hardly qualify as an
amplifier in the scheme of things. I was crazy about electronics, but
realized early on I didn't have what it took. I was always somewhat
confused by things, very unlike machining. I made up my mind in high
school that I'd pursue machining and give up my quest to learn electronics.
When solid state devices hit the market, I was all the more confused. I
think I made a sound decision considering my aptitude for such things.


Assuming I live long enough to finish what appears to be an interminable
project, I'll give a report on my level of satisfaction. Don't hold
your
breath!

Good Luck,
DoN.

Chuckle! That I can use!

Thanks, DoN.

Harold